SP 14 Built

I have been following this forum since April and digged into all SP14 builts. Meanwhile I have been following many alternative DIY Valve Pre kits. After long consultancies with my friends who are more experienced in tube world here in Turkey, I have decided to make SP14.Till now I made Jensen 1071 Speakers (of Troels Gravesen), Lampucera DAC (DAC kit from HongKong mod. by Lukas Ficus), BoozhoundLab Pacific Phono Pre, so I had some soldering skills without detailed electronic knowledge... All were figured out from manuals of parts...

Finally week ago, I have completed my SP 14. Due to high transportation cost to Turkey, I supplied from Roy, PCB and its components. Hereby I have to thank to Roy. During all my DIY background, I had correspondances with many suppliers around World, Roy was the most responsive of them. He answered to all my questions (may be even to some silly ones , as its my first complicated project ).

It was a week I have completed , left channel was ok but I could not get sound from right channel. Later I figured out, that I have soldered signal cable and ground shifted. Then I controlled it is ok.Now just at the beginning I have very tiny deep crackles at right channel, which goes after warming up.Then deep silent kit.

http://illiweb.com/fa/pbucket.gif

More detailed photos are at https://plus.google.com/105041940468126077194/posts/HKzZmAhkZ8d

Thanks a lot. It was challenging for me. Sandpapering wooden part 5 times starting with no. 600 sandpaper, polishing and no.800 then polish up till no. 1200 sandpaper and final polish. Second challenging part was the front back and top covers. They are stainless steel so I had to define exactly all holes and openings make autocad drawing with a friend and give the workshop. Hopefully everything went well.

As for sound. Honestly I did not get this performance from my system. Jensen speakers were waiting for this pre Main differences were at low frequencies and high frequencies. Even with those Russian PIO s getting this performance was super. After burn in period, it will be a different world for sure. I have checked different tube second hand pre's. Do not want to name them, but even they were burned in already, did not gave this performance. We will compare in couple of months with some other tube pre kits (ebay) of my friends here.

Like the look..vary good work thanks for the pic...only thing i had that looks close was my old hhscott 355 pretuner ,299c,b,a...pure gold.... sweet like honey....i relly like the Big Tone of 6SN7...i have put some in the front end of dynaco MK3s....

Jeff V. wrote:Is that one of the Takman stepped attenuators from Ebay? Is the switch good quality? How do you like it?Nice build!

-Jeff

Thanks Jeff. Thats correct takman stepped attenuator from ebay. Full metal body very strong built, no crackle, no unwanted noise during volume up and down. I realy liked it. Additionaly due to well located in and outs no danger if ground touches signal or not. No need for a precaution.

Tiguan yes, very nice.The 15 seconds of noise you hear at start-up is probably just the tubes warming up. I get a nasty open-ground sound from my SP-13 at about 8 seconds, then it goes away. An easy cure is to start the preamplifier first, wait a minute, then light the power amp(s).

deepee99 wrote:Tiguan yes, very nice.The 15 seconds of noise you hear at start-up is probably just the tubes warming up. I get a nasty open-ground sound from my SP-13 at about 8 seconds, then it goes away. An easy cure is to start the preamplifier first, wait a minute, then light the power amp(s).

It has been almost 8 weeks that I have completed my SP14. I listen music everyday min 2 hour. Today morning I realised that I made the best thing by making this SP14.to fine tune thé system İ could not have a better opportunity. Just by changing 2 tubes you can jump to a different league. İ started by 4 quad matches Sylvania I guess 60's GTB Chrome tops. Friday İ received 2 matched RCA GT and 2 Raytheon GT s. Today morning İ took all 4 Sylvania GTB s and put 2 rca to the gain and 2 matched raytheon to the buffer.

Opened jriver. And wow. My wife was telling why you are smiling so (which İ was not aware I do ) It became a wonderful step for me. After this experience I ordered immediately 2 matched Sylvania vt231 from 40's which was in my watchlist at ebay. SP14 is a very responsive design. What you will do you get the result which is perfect...

Here comes a question..Which position do you think that affect more, between gain and buffer. Sure need to be tried but as a start point if you will change Just 2 tubes which 2 you would replace gain or buffer.From the other thread relating microphonic, better tubes to gain. Microphonic to buffer.understood !!!

But in my case, for better performance if microphonic is not an issue, better tubes to gain or buffer.

It has been almost 4 months that I have been completed my Sp14 pre. Since then I have supplied some tubes, those are as follows;

- 4 quad matched Sylvania GTB Chrome top

- 2 matched Sylvania VT 231

- 2 matched RCA 6SN7 GTB

- 2 matched Raytheon 6SN7 GTB

Based on my personal taste, my ranking is 1. Sylvania VT 2312. Sylvania GTB Chrome top ( a price/performance tube, detailed, airy, big and seperated sound stage but not silky and not tube type romantic I could not explain different way what I mean ) 3. RCA GTB (not bad but not as detailed like top 2 and even not as airy as Sylvania GTB Chrome top)4. Raytheon GTB (actually I did not like at all)

BEST MATCH I had Sylvania VT231 at input and Sylvania GTB Chrome top as output.

I wonder how 1578 and 5692 tubes will be. I am not a bass addicted guy and listen mainly Jazz trio, quartet ... groups , vocal albums and classical, so I am not after KenRad VT231 which is talked generally one of the best bass.

I will be glad if other sp14 owners will share their opinions about tubes they have. Because not every tube acts the same in every tubepre with schematic design.Also did you check if rectifier tube makes difference... Because at some designs makes and some dont, as I read at some forums.